JP2012203552A - Input device, display device, and portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input device, a display device and a portable terminal which can reduce such sound occurrence that a user can hear, and also can give a user an adequate tactile impression.SOLUTION: An input device comprises: a touch panel 3 for receiving input by pressing force; a piezoelectric element (load detection unit) 4 for detecting a pressing load on the touch panel 3; a piezoelectric element (vibration unit) 4 for vibrating the touch panel 3; and a control unit 8 for, when the pressing load detected by the load detection unit 4 meets predetermined criteria, driving the vibration unit 4 by outputting driving signals. Taking the largest signal change rate among a plurality of signal change rates of the driving signals for a maximum signal change rate, the maximum signal change rate of the driving signals is larger than a maximum signal change rate of a sine wave and is equal to or less than three.

Description

  The present invention relates to an input device, a display device, and a mobile terminal that can transmit a tactile sensation to a user.

  In recent years, when a user operates an input unit such as a touch panel, tactile transmission technology is known that transmits various tactile sensations such as a pressing feeling, a tracing feeling, and a feeling of touch to the operated user (for example, , See Patent Document 1). An input device to which such a tactile transmission technology is applied includes a vibration unit that vibrates the input unit, and the input unit vibrates according to the vibration of the vibration unit, so that a tactile sensation can be transmitted to the user. .

JP 2003-122507 A

  In the above input device, in order to vibrate the input unit, the input unit is disposed to face the display unit through a space. Further, the input unit is generally supported at its four corners by a support unit. However, in such an input device, there is a possibility that dust or water may enter from a portion not supported by the support portion between the display portion and the input portion. On the other hand, by arranging the support portion over the entire outer periphery of the input portion, the possibility of such a problem can be reduced. However, if it does in this way, the vibration by a vibration part will be prevented and sufficient tactile sensation cannot be transmitted to a user.

  On the other hand, by increasing the voltage applied to the vibration part, it is possible to solve the above problem by increasing the vibration by the vibration part, but if the vibration by the vibration part becomes too large, the input part With this vibration, there is a possibility that a sound that can be heard by the user from the input unit may be generated.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to transmit sufficient tactile sensation to the user while reducing the generation of sound that can be heard by the user. The present invention relates to an input device, a display device, and a portable terminal.

  One aspect of the input device according to the present invention is detected by an input unit that receives an input by pressing, a load detection unit that detects a pressing load on the input unit, a vibration unit that vibrates the input unit, and the load detection unit. And a control unit that drives the vibrating unit by outputting a drive signal when the pressing load satisfies a predetermined standard, and the largest signal change rate among the plurality of signal change rates of the drive signal Is the maximum signal change rate, the maximum signal change rate of the drive signal is larger than the maximum signal change rate of the sine wave and 3 or less.

  INDUSTRIAL APPLICABILITY The input device, display device, and portable terminal of the present invention have an effect that a sufficient tactile sensation can be transmitted to the user while reducing the generation of sound that can be heard by the user.

It is a top view which shows schematic structure of the display apparatus which concerns on this embodiment. It is sectional drawing cut | disconnected along the cutting line II shown in FIG. It is sectional drawing cut | disconnected along the cutting line II-II shown in FIG. It is a block diagram which shows schematic structure of the said display apparatus. It is the figure which represented the drive signal as a drive waveform. The table shows the measurement results of the amount of touch panel deflection when the maximum signal change rate is changed and whether or not there is enough sound to be heard by the user due to the vibration of the touch panel. It is a figure. It is a figure which shows the example in case the drive waveform of a drive signal is a triangular wave. It is a figure which shows the example in case the drive waveform of a drive signal is a sine wave. It is a figure which shows the example in case the drive waveform of a drive signal is a waveform of a Gaussian function. It is a flowchart which shows the operation example of the input device which concerns on this embodiment. It is a perspective view which shows schematic structure of the portable terminal which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  However, for convenience of explanation, the drawings to be referred to below show simplified main members necessary for explaining the present invention, among the constituent members of one embodiment of the present invention. Therefore, the input device, the display device, and the mobile terminal according to the present invention can include arbitrary constituent members that are not shown in the drawings referred to in this specification.

  As shown in FIGS. 1 to 4, the display device X <b> 1 according to the present embodiment includes a liquid crystal display panel 2, a touch panel 3, a piezoelectric element 4, a base body 5, a frame body 6, a support unit 7, and a control unit 8. Yes. The touch panel 3, the piezoelectric element 4, and the control unit 8 are an embodiment of the input device according to the present invention. 1 to 3, the control unit 8 is not shown for convenience of explanation.

  The liquid crystal display panel (display unit) 2 is a display panel that uses a liquid crystal composition for display. Specifically, the liquid crystal display panel 2 includes a first substrate, a second substrate disposed to face the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate, A display member layer interposed between the substrate and the second substrate and contributing to display. Examples of the display member layer include a pixel electrode, an alignment film, and a color filter. The driving method of the liquid crystal display panel 2 may be a simple matrix driving method or an active matrix driving method. The liquid crystal display panel 2 may be a monochrome display panel or a color display panel.

  Instead of the liquid crystal display panel 2, a display panel such as a plasma display, an organic EL display, or electronic paper may be used.

  The touch panel (input unit) 3 is an input device that detects a position operated by a user with a finger or a pen as an input position. As shown in FIGS. 2 and 3, the touch panel 3 is disposed to face the liquid crystal display panel 2 via the space S <b> 1. The touch panel 3 has an operation surface 3a and a back surface 3b located on the opposite side of the operation surface 3a. That is, the operation surface 3a of the touch panel 3 is a surface operated by the user with a finger or a pen. Examples of the method of the touch panel 3 include a capacitance method, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and the like.

The piezoelectric element (vibration unit) 4 is a member that plays a role of vibrating the touch panel 3 when a predetermined standard for receiving an input to the touch panel 3 is satisfied. In the present embodiment, the piezoelectric element 4
Are provided on the back surface 3 b of the touch panel 3 along the short side of the touch panel 3. The number and arrangement position of the piezoelectric elements 4 are not particularly limited. In the present embodiment, the piezoelectric element 4 is a unimorph.

  The piezoelectric element (load detection unit) 4 is also a member that plays a role of detecting a pressing load on the touch panel 3. Specifically, when the user presses the operation surface 3a of the touch panel 3, the touch panel 3 bends downward. The piezoelectric element 4 also bends according to the downward deflection of the touch panel 3. That is, the amount of deflection of the piezoelectric element 4 changes according to the pressing load on the touch panel 3. The piezoelectric element 4 converts it into a voltage corresponding to the amount of deflection. For this reason, the pressing load on the touch panel 3 can be detected by the piezoelectric element 4. In place of the piezoelectric element 4, a load sensor such as a strain sensor may be employed.

  The base body 5 and the frame body 6 are members that serve to accommodate the liquid crystal display panel 2. A liquid crystal display panel 2 is provided on the upper surface 5 a of the base 5. The frame 6 is provided on the upper surface 5 a of the base 5 so as to surround the liquid crystal display panel 2 and the touch panel 3. Examples of the constituent material of the base body 5 and the frame body 6 include resins such as polycarbonate and metals such as stainless steel, aluminum, and magnesium alloys. Here, the base body 5 and the frame body 6 may be formed integrally, or may be formed separately and independently.

  The support portion 7 is a member that plays a role of supporting the touch panel 3. The support portion 7 is provided on the upper surface 5 a of the base body 5. That is, the support portion 7 is located between the outer peripheral portion of the back surface 3 b of the touch panel 3 and the upper surface 5 a of the base 5. Since the support part 7 is provided in the outer peripheral part in the back surface 3b of the touch panel 3, possibility that dust or water will permeate into the space S1 between the liquid crystal display panel 2 and the touch panel 3 can be reduced. Thus, the display device X1 adopts a dustproof and waterproof structure. Here, the support part 7 has elasticity so as not to suppress the vibration of the touch panel 3. Examples of the constituent material of the support portion 7 include, for example, poron, silicone rubber, urethane rubber, urethane foam, other rubbers, plastic, and stainless steel.

  The control unit 8 is a member that plays a role of driving the piezoelectric element 4 by outputting a drive signal when the pressing load detected by the piezoelectric element 4 satisfies a predetermined reference. That is, the control unit 8 records threshold information indicating the predetermined standard in a memory (not shown) in the control unit 8 in advance in order to determine whether or not the predetermined standard is satisfied.

  FIG. 5 is a diagram showing drive signals as drive waveforms. In FIG. 5, the voltage is shown on the vertical axis and the time is shown on the horizontal axis. In the present embodiment, the largest signal change rate among the plurality of signal change rates of the drive signal is defined as the maximum signal change rate. Further, the signal change rate A is expressed by the following formula 1. That is, as shown in FIG. 5, in the following formula 1, t1 represents a certain arbitrary time, and V1 represents a voltage value at t1. T2 represents an arbitrary time larger than t1, and V2 represents a voltage value at t2. V0 indicates the maximum value of the voltage. That is, the signal change rate A is a value expressed by normalization by dividing the time gradient of the voltage value by the maximum value V0 of the voltage.

  In the present embodiment, the signal change rate is calculated by sampling every 0.025 msec in a period from 0 sec to the time when the cycle ends (for example, 2.5 msec if the frequency of the drive signal is 400 Hz). Among the calculated signal change rates, the largest signal change rate was defined as the maximum signal change rate.

  FIG. 6 shows the amount of deflection of the touch panel 3 when the maximum signal change rate is changed and set, and whether or not a sound that can be heard by the user is generated with the vibration of the touch panel 3. It is the figure which showed the result of having carried out with the table | surface. Note that in the “generation of sound” shown in FIG. 6, a circle indicates that no sound that can be heard by the user is generated. Moreover, the x mark represents that a sound that can be heard by the user is generated. 6 shows the case where the frequency of the drive signal is 300 Hz, and the lower part of FIG. 6 shows the case where the frequency of the drive signal is 400 Hz.

  In the above measurement, an acrylic panel having a length of 105.7 mm, a width of 45.8 mm, and a thickness of 1.48 mm was used as an alternative to the touch panel 3 in the present embodiment. Further, as the support portion 7, 1 mm thick poron was used. The support part 7 was arrange | positioned over the outer periphery of the acrylic panel. As an alternative to the substrate 5 and the frame 6, a SUS plate having a length of 120 mm, a width of 60 mm, and a thickness of 5 mm was used. That is, an acrylic panel was disposed on the SUS plate via the support portion 7. In addition, two piezoelectric elements 4 are arranged along one long side of the acrylic panel, two on the back side of the acrylic panel, and two along the other long side of the acrylic panel, two on the back side of the acrylic panel. . In this state, various drive signals having different maximum signal change rates were input to the piezoelectric element 4, and the acrylic panel was vibrated, and the amount of deflection at the center of the acrylic panel was measured using a laser Doppler velocimeter. . In the following, the deflection amount of the acrylic panel is shown as the deflection amount of the touch panel 3.

As shown in the upper part of FIG. 6, when the frequency of the drive signal is 300 Hz and the drive waveform of the drive signal is the triangular wave shown in FIG. 7, no sound that can be heard by the user is generated, and The amount of deflection of the touch panel 3 was 63.0 μm. In this case, the maximum signal change rate is 0.6. Further, when the drive waveform of the drive signal is the sine wave shown in FIG. 8, a sound that can be heard by the user is not generated, and the deflection amount of the touch panel 3 is 72.1 μm. In this case, the maximum signal change rate is 0.94.
Here, the sine wave is a drive waveform represented by the following formula 2. That is, as shown in FIG. 8, in the following formula 2, T indicates a period.

  In addition, when the drive waveform of the drive signal is a waveform of a degree 3 Gaussian function shown in FIG. 9, a sound that can be heard by the user is not generated, and the deflection amount of the touch panel 3 is 72.5 μm. there were. In this case, the maximum signal change rate is 1.09. Further, when the drive waveform of the drive signal is a waveform of a degree 4 Gaussian function shown in FIG. 9, a sound that can be heard by the user is not generated, and the deflection amount of the touch panel 3 is 77.5 μm. there were. In this case, the maximum signal change rate is 1.46. In this way, the order of the Gaussian function was changed from 5 to 10, and the amount of deflection of the touch panel 3 was measured to determine whether or not a sound that could be heard by the user was generated.

  Here, the waveform of the Gaussian function is a drive waveform represented by the following Equation 3. That is, as shown in FIG. 9, in the following formula 3, m represents the order. T indicates a cycle.

  As a result, when the drive waveform of the drive signal is a Gaussian function waveform of order 2 shown in FIG. 9, a sound that can be heard by the user was generated. Further, when the driving waveform of the driving signal is a Gaussian function waveform of orders 9 and 10, the amount of deflection of the touch panel 3 is smaller than when the driving waveform of the driving signal is a sine wave. That is, when the drive waveform of the drive signal is a Gaussian function waveform of order 3 to 8, no sound that can be heard by the user is generated, and the amount of deflection of the touch panel 3 is sufficiently large. In other words, when the maximum signal change rate is larger than the maximum signal change rate of the sine wave and equal to or less than 3, no sound that can be heard by the user is generated, and the amount of deflection of the touch panel 3 Will be big enough.

Similarly to the above, when the frequency of the drive signal was 400 Hz, whether or not a sound that could be heard by the user was generated, and the amount of deflection of the touch panel 3 were measured. As shown in the lower part of FIG. 6, when the drive waveform of the drive signal is a waveform of a Gaussian function of degree 2 shown in FIG. 9, a sound that can be heard by the user was generated. When the drive waveform of the drive signal is a Gaussian function waveform of order 7 to 10, the amount of deflection of the touch panel 3 is smaller than when the drive waveform of the drive signal is a sine wave. That is, when the drive waveform of the drive signal is a Gaussian function waveform of order 3-6, no sound that can be heard by the user is generated, and the amount of deflection of the touch panel 3 is sufficiently large. In other words, when the maximum signal change rate is larger than the maximum signal change rate of the sine wave and equal to or less than 3, no sound that can be heard by the user is generated, and the amount of deflection of the touch panel 3 Will be big enough.

  As described above, when the frequency of the drive signal is 300 Hz or more, when the maximum signal change rate is larger than the maximum signal change rate of the sine wave and 3 or less, there is a sound that can be heard by the user. It does not occur and the amount of deflection of the touch panel 3 becomes sufficiently large. That is, the control unit 8 outputs a drive signal having a maximum signal change rate of 3 or less to the piezoelectric element 4 that is greater than the maximum signal change rate of the sine wave. The piezoelectric element 4 vibrates according to the drive signal output from the control unit 8.

  Next, an operation example of the input device according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 10, when the user presses the operation surface 3a of the touch panel 3, the piezoelectric element 4 detects a pressing load on the touch panel 3 (Op1). Then, when the pressing operation by the user is a pressing operation on the input object displayed on the liquid crystal display panel 2, the control unit 8 determines whether or not the pressing load detected at Op1 satisfies a predetermined criterion. Is determined (Op2). The control unit 8 is provided, for example, on an FPC (Flexible Printed Circuit) for applying a voltage to the touch panel 3 together with a position detection driver that controls the touch panel 3.

  If the control unit 8 determines that the pressing load detected at Op1 satisfies a predetermined standard (YES at Op2), the control unit 8 outputs a drive signal to the piezoelectric element 4 (Op3). Note that, as described above, this drive signal is a signal having a maximum signal change rate that is larger than the maximum signal change rate of the sine wave and 3 or less. Then, the piezoelectric element 4 vibrates in accordance with the drive signal output at Op3 (Op4). Then, the touch panel 3 vibrates by the piezoelectric element 4 vibrated at Op4 (Op5). Thereby, sufficient pressing feeling is transmitted to the user who pressed the operation surface 3a of the touch panel 3. On the other hand, if it determines with the press load detected in Op1 not satisfy | filling the predetermined reference | standard (NO in Op2), the control part 8 will complete | finish the process of FIG.

  As described above, the input device and the display device X1 according to the present embodiment can transmit sufficient tactile sensation to the user while reducing the generation of sound that can be heard by the user.

  Next, the portable terminal Y1 provided with the display device X1 will be described with reference to FIG.

  As shown in FIG. 11, the portable terminal Y <b> 1 includes a display device X <b> 1, a housing 10, and operation keys 11. The housing 10 is a member that plays a role of housing the display device X1. The operation key 11 is a key input by the user. The operation key 11 may be an operation key displayed on the display screen, or may be an operation key that physically exists. The mobile terminal Y1 is, for example, a mobile phone, a smartphone, or a PDA. Since the portable terminal Y1 includes the display device X1 in the housing 10, it is possible to transmit sufficient tactile sensation to the user while reducing generation of sound that can be heard by the user.

  The display device X1 is various devices such as a programmable display, an electronic notebook, a personal computer, a copying machine, a game terminal device, a television, a digital camera, etc. used for industrial purposes instead of the portable terminal Y1. May be provided.

X1 display device Y1 portable terminal 2 liquid crystal display panel (display unit)
3 Touch panel (input unit)
4 Piezoelectric elements (vibration part, load detection part)
8 Control unit 10 Case

Claims (5)

An input unit for receiving an input by pressing;
A load detection unit for detecting a pressing load on the input unit;
A vibrating section for vibrating the input section;
A control unit that outputs a drive signal to drive the vibration unit when the pressing load detected by the load detection unit satisfies a predetermined standard; and
When the largest signal change rate among the plurality of signal change rates of the drive signal is the maximum signal change rate,
The maximum signal change rate of the drive signal is larger than the maximum signal change rate of the sine wave and is 3 or less.   The input device according to claim 1, wherein a frequency of the drive signal is 300 Hz or more.   The input device according to claim 1, wherein the drive signal is expressed as a drive waveform of a Gaussian function. The input device according to any one of claims 1 to 3,
A display unit disposed opposite to the input device.   The portable terminal which equipped the housing | casing with the display apparatus of Claim 4.

Images